Methods of manufacturing and using a flowable cement-based material

ABSTRACT

Methods of manufacture and use of flowable materials are provided. The flowable fill materials include a cement-based fill material with a cement component and an aggregate component that are mixed with a chemical agent and the like in water. This provides the cement-based material in a flowable state that can be controllably set over time.

CROSS REFERENCE TO RELATED APPLICATION

The present application is divisional of U.S. patent application Ser.No. 11/424,154 filed on Jun. 14, 2006, which is a continuation of U.S.patent application Ser. No. 11/378,572 filed on Mar. 17, 2006, nowabandoned, which is a continuation of U.S. patent application Ser. No.11/190,637, filed on Jul. 27, 2005, now abandoned, which claims priorityto U.S. Patent Application No. 60/592,054 filed on Jul. 28, 2004, thedisclosures of which are incorporated herein by reference.

BACKGROUND

The present invention generally relates to flowable materials. Morespecifically, the present invention relates to flowable cement-basedmaterials and methods of manufacture and use of same.

In general, a number of different fill materials are known and used. Inuse, the fill material is typically placed into an open area such thatthe open area is filled with the fill material in at least a substantialamount. The fill material can then be covered or capped with anadditional layer or layers of material, such as a ready-mix concrete.

One common type of fill material includes sand, rock, gravel and/orother like materials. This type of material is routinely placed into thefill area in a layered configuration. However, the use of this type offill material can be problematic. For example, the use of sand-type fillmaterials and the like may be difficult when applied to areas, such asconfined spaces. In this regard, additional handling of this type ofmaterial may be necessary to ensure that the confined space isadequately filled with the fill material. Further, the use of sand-typematerials and the like may require additional preparation to the areaprior to filling the area. For example, excavation may be required toprepare and ready the area for filling purposes, particularly as appliedto undercut areas.

Other types of known fill material include flowable fill materials, suchas controlled low-strength mixtures (CLSM) and the like. One type offlowable fill material is disclosed in U.S. Pat. No. 4,374,672. Thistype of fill material has fly ash as its major constituent. The fillmaterial includes 45-80% by weight of fly ash. As further disclosed, thefill material is produced and deposited under water to construct acauseway across a body of water.

Another type of flowable fill material is disclosed in U.S. Pat. No.5,951,751. This type of flowable fill material is a lime-based CLSM thatdoes not require cement or other self-setting adhesive products toachieve its desired strength and mechanical properties.

Due to its flowable nature, the flowable fill material, in general, canmore effectively fill an open area or space as compared to conventionalnon-flowable fill materials, such as with respect to sand-type fillmaterials and the like as previously discussed. However, the use ofknown flowable fill materials can be problematic as these types ofmaterials are known to prematurely set or harden during use.

A need therefore exists to provide improved flowable materials that canbe readily handled for effective use, such as a fill material.

SUMMARY

The present invention generally relates to flowable materials. Morespecifically, the present invention relates to flowable cement-basedmaterials and methods of manufacture and use of same.

The flowable cement-based materials of the present invention include acement component and an aggregate component that are mixed with achemical agent and water to provide a flowable state. The chemicalagent, such as an air-entraining agent, and water are added in aneffective amount such that the flowable state can be controllably formedinto a settable state. In this regard, the set characteristics of theflowable material can be controlled by varying the amount of chemicalagent and water, and thus not controlled by the amount of cement and/orother like materials that may be added to the flowable material.

To this end, in an embodiment the present invention provides anair-entrained cement-based material. The air-entrained cement-basedmaterial includes an aggregate component that is mixed in water andabout 2% or less by weight of an air-entraining agent to form theair-entrained cement-based material in a flowable state that includesabout 1% or less by weight of cement.

In an embodiment, the flowable state is controllably settable by theair-entraining agent and water that is added to the flowable state.

In an embodiment, the amount of water includes about 20% by weight orless.

In an embodiment, the flowable state is settable to a settable stateafter about 5 minutes to about 24 hours.

In an embodiment, the settable state is diggable at about 100 psi orless of force, such as at about 75 psi or less of force.

In an embodiment, the air-entrained cement-based material furthercomprises one or more chemical agents, such as a water reducing agent, anon-chloride accelerator, and the like.

In an embodiment, the air-entrained cement-based material does notinclude fly ash.

In another embodiment, the present invention provides a flowablecement-based material. The flowable cement-based material includes acement component at about 1% by weight or less; an aggregate componentat about 75% by weight or greater; a water component ranging from about11% by weight to about 17% by weight; and a chemical agent at about 2%by weight or less wherein the chemical agent at least includes anair-entraining agent.

In an embodiment, the cement component includes Portland cement.

In an embodiment, the flowable cement-based material further comprisesone or more cementitious materials, such as ground granulated blastfurnace slag, cement kiln dust and combinations thereof, in an amount ofup to about 2% by weight or less.

In an embodiment, the chemical agent further comprises an additionalchemical agent, such as a water reducing agent, a non-chlorideaccelerator, and combinations thereof.

In an embodiment, the aggregate component includes a fine aggregatematerial.

In an embodiment, the fine aggregate material is about ⅜ inches or lessin size.

In yet another embodiment, the present invention provides a method ofpreparing a cement-based material in a flowable state. The methodincludes providing a cement component, an aggregate component, and achemical agent at least including an air-entraining agent; mixing andfurther processing the cement component, the aggregate component and thechemical agent in water; and forming the flowable state at about 1% orless by weight of the cement component, at about 75% or more by weightof the aggregate component, at about 20% or less by weight of water, andat about 2% or less by weight of the chemical agent.

In an embodiment, the flowable state is set in a controlled manner byaddition of water and the chemical agent to the flowable state.

In an embodiment, the flowable state is set after about 10 minutes ormore.

In an embodiment, the cement component includes Portland cement.

In an embodiment, the aggregate component includes a fine aggregatematerial that complies with ASTM C 33.

In an embodiment, the chemical agent includes an additional chemicalagent, such as a water reducing agent, a non-chloride accelerator, andcombinations thereof.

In still yet another embodiment, the present invention provides a methodof filling an area with a flowable cement-based material. The methodincludes preparing the flowable cement-based material including a cementcomponent and an aggregate component that are mixed with a chemicalagent including an air-entraining agent and water; and filling the areawith the flowable cement-based material wherein the flowablecement-based material includes about 1% by weight or less, about 2% byweight or less of the chemical agent and about 20% by weight or less ofwater allowing the flowable cement-based material to be set in acontrolled manner.

In an embodiment, the flowable cement-based material is controllably setand subsequently a material layer that includes concrete is placed overthe set material for backfilling purposes.

In an embodiment, the flowable cement-based material is used to fill anundercut area.

In an embodiment, the flowable cement-based material can support theundercut area without having to remove at least a portion of theundercut area.

In an embodiment, the flowable cement-based material is used to fill aconfined space.

In an embodiment, the flowable cement-based material is set in acontrolled manner in about 5 minutes or more.

An advantage of the present invention is to provide improved flowablematerials.

Another advantage of the present invention is to provide improvedmethods of manufacture and use regarding flowable cement-basedmaterials.

Yet another advantage of the present invention is to provide improvedbackfilling materials and uses thereof.

Still yet another advantage of the present invention is to provide aflowable cement-based material that can be poured and set into aconfined space without the need for personnel to be in the confinedspace for proper placement and consolidation.

A further advantage of the present invention is to provide a flowablecement-based material that has controllable set characteristics.

Another advantage of the present invention is to provide a flowablecement-based material that has fast and effective set characteristics.

Yet a further advantage of the present invention is to provide aflowable fill material that can be used to support undercut conditionsassociated with various municipal repair jobs and the like.

Still yet a further advantage of the present invention is to provideflowable fill materials that can allow rapid reconstruction and repairof an area to be filled with the flowable material.

Additional features and advantages are described herein, and will beapparent from, the following Detailed Description.

DETAILED DESCRIPTION

The present invention generally relates to flowable materials andmethods of manufacture and use regarding same. In particular, thepresent invention relates to flowable cement-based materials.

The flowable materials of the present invention at least include acement component and an aggregate component that are mixed with one ormore chemical agents or additives and water in a sufficient amount. Thisprovides a cement-based material in a flowable state that can be set ina controlled manner. In this regard, the cement or other likecementitious materials are not utilized as the primary component forcontrolling the set characteristics of the flowable material of thepresent invention. Applicants have discovered that the setcharacteristics can be effectively controlled by adding an effectiveamount of a chemical agent including an air-entraining agent in additionto water to the cement and aggregate components. The amount of cement orother like material is then utilized to control the ultimate strength ofthe material over the long-term of use, such as at or beyond 28 daysfrom the initial set point of the flowable material.

While not being bound to any particular theory, it is believed that theaddition of the chemical agent and water in an effective amount allowsthe material components of the flowable material to be mixed in ahomogenous manner. This can promote control of the set characteristicsof the flowable materials. For example, the homogenous mixing can act tominimize, or effectively eliminate, the formation of a cementitious overlayer upon setting of the flowable material. The formation of thecementitious over layer may cause the set product to have undesirablestrength and mechanical properties.

The homogenous mixing may also facilitate control of the set time of theflowable product. The set time can be varied depending on the specificneeds of the application. In an embodiment, the set time can beeffectively controlled at about 5 minutes or more, such from about 10minutes to about 24 hours, preferably about one hour, by the addition ofone or more chemical agents that at least includes an air-entrainingagent in addition to water as previously discussed. The controllable setcharacteristics of the flowable materials can facilitate use of same.For example, the flowable materials can be effectively utilized as afill material in a variety of different applications to provide rapidand effective reconstruction and repair of areas, such as undercuts,street cuts, confined spaces and other suitable areas in need ofreconstruction and repair.

Further, the addition of air at sufficient levels and in microscopicform (i.e., bubbles) via an air-entraining agent can promote thecontrollable set characteristic of the flowable material that has a lowcement content, such as about 1% by weight or less. In addition topromoting mixing, the air is believed to allow the material to retain aneffective amount of water that is necessary to cause the flowablematerial to set in a controlled manner. As previously discussed, thematerial can be set in about 5 minutes or more after which time the setmaterial has a sufficient amount of compaction strength for use.

Upon setting, the material is effectively non-corrosive with respect toobjects, such as pipes and the like, that are encased in the setmaterial during use. As previously discussed, the flowable material ofthe present invention does not include fly ash pursuant to an embodimentand thus further promotes the non-corrosive nature of the material.

The flowable materials of the present invention can include any number,amount and suitable types of material components. In an embodiment, theflowable materials at least include a cement component, an aggregate andat least further includes a chemical agent including an air-entrainingagent in addition to water in a sufficient amount to effectively controlthe set characteristics of the flowable material. The cement componentin an embodiment includes Portland cement, preferably types I-V orcombinations thereof. In addition, the cement component can furtherinclude other material components, such as ground granulated blastfurnace slag, kiln dust, cement kiln dust, the like, and combinationsthereof. The additional cement components can be derived from anysuitable materials and in any suitable manner. For example, the kilndust can be derived from the manufacture of Portland cement.

In an embodiment, the cement component includes about 1% by weight orless. The amount of cement component can be increased up to about 3% byweight such as where about 1% by weight or less of Portland cement orthe like is used in combination with one or more other cementitiousmaterials including ground granulated blast furnace slag, cement kilndust and the like.

The aggregate component can include any suitable type of aggregate. Inan embodiment, the aggregate includes a fine aggregate, such as a fineaggregate that complies with ASTM C 33. The fine aggregate can includeany suitable size, preferably about ⅜ inches or less in size. Theaggregate material can include natural materials, manufactured aggregatematerials or combinations thereof. In an embodiment, the naturalaggregate material is native to the area where the flowable material ismanufactured and used, surrounding areas thereof, other suitable andcompatible types of materials, and combinations thereof. For example,the flowable material was made with sand that was native to an area andsurrounding areas thereof where the flowable material was field testedas described in greater detail below pursuant to an embodiment.

The manufactured fine aggregates can include recycled materials,reclaimed materials, the like or combinations thereof. For example, themanufactured fine aggregates can include quarry waste products. In anembodiment, the aggregate component includes about 75% by weight ormore, preferably about 75% by weight to about 86% by weight of theflowable material.

The water component in an embodiment includes at about 20% by weight orless of the flowable material. Preferably, the water component includesabout 11% by weight to about 17% by weight. The water component can bederived from any suitable water source for processing purposes. In anembodiment, the water component includes potable water, recycled orreclaimed water, such as from the production of concrete, the like orcombinations thereof.

As previously discussed, Applicants have discovered that the setcharacteristics can be effectively controlled by varying the amount ofchemical agent added to the flowable material. The chemical agent atleast includes an air-entraining agent. In addition, the chemical agentcan include a non-chloride accelerator, a water reducing agent, the likeor mixtures and combinations thereof. The addition of these types ofagents can promote fast and effective set characteristics, such aswithin about 5 minutes or more, preferably within about 1 hour or more.

In an embodiment, the chemical agent includes about 2% by weight or lessof the flowable material for effective control of the setcharacteristics. For example, the air-entraining agent can be added atabout 2.0 ounces per 100 pounds of cement or more, where additionaltypes of chemical agents including non-chloride accelerators and thelike can be added at about 100 ounces per 100 pounds of cement or more.The chemical agent can include any suitable type of material, such asany suitable type of commercially-available product. For example, theair-entraining agent includes MBVR in standard or concentrate that iscommercially-available from DEGUSSA ADMIXTURES, INC. and/or other typesof suitable and compatible materials.

The material components of the flowable material can be added in anysuitable amount, such as any suitable amount within the defined weightpercentages associated with each component as defined herein. In anembodiment, the cement component ranges from about 25 pounds per cubicyard to about 40 pounds per cubic yard; the aggregate component rangesfrom about 3090 pounds per cubic yard to about 3130 pounds per cubicyard; the water component ranges from about 60 gallons per cubic yard toabout 70 gallons per cubic yard; the air entraining component rangesfrom about 2.0 ounces per 100 pounds of cement to about 5.0 ounces per100 pounds of cement; and an additional chemical agent (e.g.,non-chloride accelerator) ranges from about 100 ounces per 100 pounds ofcement to about 150 ounces per 100 pounds of cement.

The flowable materials of the present invention can be manufactured inany suitable manner. In general, the various components of the flowablematerials are mixed and further processed in a sufficient amount ofwater such that the desired mechanical properties, strength propertiesand the like can be achieved. The flowable product can include a numberof different material components, such as the cement component and theaggregate component mixed with the air-entraining agent in addition toother types of chemical agents and water as previously discussed.

The material components once processed form a liquid and flowable state.After a desired period of time, the flowable state can set to a settablestate in a controlled manner. As previously discussed, Applicants havediscovered that the set characteristics can be controlled by varying theamount of water and chemical admixtures, such as air-entraining agentsin addition to other types of chemical agents, such as non-chlorideaccelerators and the like, and thus not primarily rely on cementitiousmaterials, pozzolanic materials, the like, or combinations thereof forsuch purpose.

In an embodiment, the flowable materials are processed in a redi-mixconcrete batch plant and once processed can be delivered for use in aredi-mix concrete truck. The flowable materials of the present inventionin an embodiment have a shelf life of at least up to about three hours.Further, the flowable material in flowable form can remain shelf-stableover temperatures that range from about 40° F. to about 100° F., such asambient temperatures. Specific manufacturing procedures are providedpursuant to an embodiment as follows:

-   -   1. All ingredients except liquid chemical admixtures and water        are measured by mass. Liquid chemical admixtures are measured by        volume. Water can be measured by volume or mass.    -   2. All measurements are taken according to the tolerances        established in ASTM C 94.    -   3. Once all of the ingredients have been properly measured, the        ingredients are introduced into the mixing apparatus as follows:        -   a) Approximately 75% by weight of the total batch water            (adjusted for aggregate moisture) is introduced along with            the air-entraining admixture.        -   b) The fine aggregate is added at an even flow under a            steady loading sequence. After about 25% by weight of the            fine aggregate has been introduced, the cement and other            cementitious materials are added at an even flow under a            steady loading sequence and are to be completely introduced            before the last approximate 25% by weight of the fine            aggregate is introduced.        -   c) The remaining approximate 25% by weight of the total            batch water and all other chemical admixtures are introduced            once the fine aggregate addition has been completed.        -   d) The batch is then mixed with the proper number of            revolutions to insure that a uniform mass is created            throughout the batch according to ASTM C 94.

The mixing apparatus can include any suitable type. For example, themixing apparatus in an embodiment can include a central mix batch plant,a transit mix batch plant and the like.

A preferred composition of the flowable cement-based material of thepresent invention includes about 1% by weight or less of the cementcomponent, about 75% to about 86% by weight of the aggregate component,about 11% to about 17% by weight of water, and up to and including about2% of the chemical admixture, such as the air-entraining agent. In anembodiment, the bulk density of the flowable material is greater than125 pounds per cubic feet (“pcf”), preferably about 135 pcf to about 138pd. Once set, the product has a compressive strength that is about 200psi or less in an embodiment, preferably about 100 psi or less. Further,the set product in an embodiment has a diggable strength of about 100psi or less. In this regard, the set product can be readily excavatedwith conventional handheld digging tools.

Examples illustrative of the present invention are provided belowaccording to various embodiments without limitation:

Flowable Material Examples

Flowable Material Component Amount Cement (Type I)   38 lbs./yd³-40lbs./yd³ Sand (FA-2) 3090 lbs./yd³-3130 lbs./ yd³ Water   60 gal./yd³Air-Entraining Agent   2.0 oz./100 lbs. of cement POZZUTEC 20  100oz./100 lbs. of cement (non-chloride accelerator) POZZOLITH 122 HE  100oz./100 lbs. of cement (High-Early Accelerator)

Flowable Material Component Amount Cement (Type I)   38 lbs./yd³-40lbs./yd³ Sand (FA-2) 3090 lbs./yd³-3130 lbs./yd³ Water   60 gal./yd³Air-Entraining Agent   2.0 oz./100 lbs. of cement POZZUTEC 20  100oz./100 lbs. of cement (non-chloride accelerator)

Flowable Material Component Amount Cement (Type I)   25 lbs./yd³ Sand(FA-2) 3130 lbs./yd³ Water   60 gal./yd³ Air-Entraining Agent   2.0oz./100 lbs. of cement POZZUTEC 20  100 oz./100 lbs. of cement(non-chloride accelerator)

A flowable material made pursuant to an embodiment has been fieldtested. The flowable material was transported to the field test site inChicago, Ill. in two redi-mix concrete trucks.

The test material was made with an aggregate material including Sand(FA-2) that was native to the test area and surrounding areas thereof.However, any suitable and compatible aggregate materials can be utilizedas previously discussed. The test area to be filled was an excavatedarea in size of about 2500 cubic feet.

The test area was filled over a period of about 15 minutes. The totalamount of flowable material used to fill the excavated area was about 9¼cubic yards. The flowable material set within about 20 minutes such thatthe set product was able to support, at a minimum, an adult's weightstanding on the material.

It should be appreciated that the flowable materials of the presentinvention can be utilized in a variety of different applications.Illustrative examples of applications associated with the flowablematerial include structural fill, backfill soil stabilization, trenchfill, tank remediation fill, excavation repair, repair of pipes forwater leaks, sub base for paving brick and pipe fill, and the like.

Preferably, the flowable materials are used as a fill material pursuantto an embodiment. The fill material can be used to reconstruct andrepair areas in need of same, such as open areas, excavated areas,street cuts, undercuts, confined spaces and/or the like. For example,the flowable materials can be utilized to assist municipalities and thelike with street and/or other types of structural repairs. The abilityof the flowable materials to provide rapid repair and reconstructionallows the area to be ready again for use within hours or less after therepair has been completed.

It should be understood that various changes and modifications to thepresently preferred embodiments described herein will be apparent tothose skilled in the art. Such changes and modifications can be madewithout departing from the spirit and scope of the present subjectmatter and without diminishing its intended advantages. It is thereforeintended that such changes and modifications be covered by the appendedclaims.

1. A method of manufacturing a cement-based material comprisingpreparing the cement-based material consisting of an aggregate componentcomposed of a sand aggregate and about 1% or less by weight of a cementthat is mixed with water and an air-entraining agent to form thecement-based material in a flowable state, wherein the cement-basedmaterial optionally consists of at least one of a water reducing agent,a non-chloride accelerator, and a cementitious material.
 2. The methodof claim 1, wherein the aggregate component is about 75% by weight orgreater, wherein an amount of water is about 20% by weight or less,wherein the air-entraining agent is about 2% by weight or less, andwherein the cementitious material is about 2% by weight or less.
 3. Themethod of claim 1, wherein the cement includes Portland cement.
 4. Themethod of claim 1, wherein the cementitious material is selected fromthe group consisting of ground granulated blast furnace slag, cementkiln dust, fly ash and combinations thereof.
 5. The method of claim 1,wherein the sand aggregate is a fine aggregate material.
 6. The methodof claim 5, wherein the fine aggregate material is about ⅜ inches orless in size.
 7. A method of filling an area with a cement-basedmaterial, the method comprising: preparing the cement-based materialconsisting of an aggregate component composed of a sand aggregate andabout 1% or less by weight of a cement that is mixed with water and anair-entraining agent to form the cement-based material in a flowablestate, wherein the cement-based material optionally consists of at leastone of a water reducing agent, a non-chloride accelerator, and acementitious material; and filling the area with the cement-basedmaterial in the flowable state.
 8. The method of claim 7, wherein thearea is selected from the group consisting of an open area, a streetcut, an undercut, a confined space, and combinations thereof.
 9. Themethod of claim 7, wherein the aggregate component is about 75% byweight or greater, wherein an amount of water is about 20% by weight orless, wherein the air-entraining agent is about 2% by weight or less,and wherein the cementitious material is about 2% by weight or less. 10.The method of claim 7, wherein the cement includes Portland cement. 11.The method of claim 7, wherein the cementitious material is selectedfrom the group consisting of ground granulated blast furnace slag,cement kiln dust, fly ash and combinations thereof.
 12. The method ofclaim 7, wherein the sand aggregate is a fine aggregate material. 13.The method of claim 12, wherein the fine aggregate material is about ⅜inches or less in size.
 14. The method of claim 7, wherein thecement-based material fills the area so as to be applied as at least oneof structural fill, backfill soil stabilization, trench fill, tankremediation fill, excavation repair, repair of pipes for water leaks,sub-base for paving bricks, and pipe fill.